*2.6. Statistical Analysis*

In order to identify genera that differ in abundance between samples from different donors, ANCOM analysis was used [30]. All additional statistics were generated using R (version 3.5.1) in the RStudio environment. Libraries such as ggplot2, cowplot and ggpubr were used for data visualization [31–33]. Except when otherwise stated, p-values of less than 0.05 were considered statistically significant.

#### *2.7. Sequencing Data Availability*

Next-generation sequencing data has been deposited and is available under the number PRJEB36368 and link www.ebi.ac.uk/ena/data/view/PRJEB36368.
